/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/****************************************************************************
 * apps/system/i2c/i2c_main.c
 *
 *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name Gregory Nutt nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <tinyara/config.h>

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <stdarg.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>

#include "i2ctool.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/****************************************************************************
 * Private Types
 ****************************************************************************/

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/

static int i2ccmd_help(FAR struct i2ctool_s *i2ctool, int argc, char **argv);
static int i2ccmd_unrecognized(FAR struct i2ctool_s *i2ctool, int argc, char **argv);

/****************************************************************************
 * Private Data
 ****************************************************************************/

struct i2ctool_s g_i2ctool;

static const struct cmdmap_s g_i2ccmds[] = {
	{"?",    i2ccmd_help, "Show help     ", NULL},
	{"bus",  i2ccmd_bus,  "List busses   ", NULL},
	{"dev",  i2ccmd_dev,  "List devices  ", "[OPTIONS] <first> <last>"},
	{"get",  i2ccmd_get,  "Read register ", "[OPTIONS] [<repititions>]"},
	{"help", i2ccmd_help, "Show help     ", NULL},
	{"set",  i2ccmd_set,  "Write register", "[OPTIONS] <value> [<repititions>]"},
	{"verf", i2ccmd_verf, "Verify access ", "[OPTIONS] [<value>] [<repititions>]"},
	{NULL, NULL, NULL, NULL}
};

/****************************************************************************
 * Public Data
 ****************************************************************************/

/* Common, message formats */

const char g_i2cargrequired[] = "i2ctool: %s: missing required argument(s)\n";
const char g_i2carginvalid[]  = "i2ctool: %s: argument invalid\n";
const char g_i2cargrange[]    = "i2ctool: %s: value out of range\n";
const char g_i2ccmdnotfound[] = "i2ctool: %s: command not found\n";
const char g_i2ctoomanyargs[] = "i2ctool: %s: too many arguments\n";
const char g_i2ccmdfailed[]   = "i2ctool: %s: %s failed: %d\n";
const char g_i2cxfrerror[]    = "i2ctool: %s: Transfer failed: %d\n";

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name: i2ccmd_help
 ****************************************************************************/

static int i2ccmd_help(FAR struct i2ctool_s *i2ctool, int argc, char **argv)
{
	const struct cmdmap_s *ptr;

	i2ctool_printf(i2ctool, "Usage: i2c <cmd> [arguments]\n");
	i2ctool_printf(i2ctool, "Where <cmd> is one of:\n\n");
	for (ptr = g_i2ccmds; ptr->cmd; ptr++) {
		if (ptr->usage) {
			i2ctool_printf(i2ctool, "  %s: %s %s\n", ptr->desc, ptr->cmd, ptr->usage);
		} else {
			i2ctool_printf(i2ctool, "  %s: %s\n", ptr->desc, ptr->cmd);
		}
	}

	i2ctool_printf(i2ctool, "\nWhere common \"sticky\" OPTIONS include:\n");
	i2ctool_printf(i2ctool, "  [-a addr] is the I2C device address (hex).  " "Default: %02x Current: %02x\n", CONFIG_I2CTOOL_MINADDR, i2ctool->addr);
	i2ctool_printf(i2ctool, "  [-b bus] is the I2C bus number (decimal).  " "Default: %d Current: %d\n", CONFIG_I2CTOOL_MINBUS, i2ctool->bus);
	i2ctool_printf(i2ctool, "  [-r regaddr] is the I2C device register address (hex).  " "Default: 00 Current: %02x\n", i2ctool->regaddr);
	i2ctool_printf(i2ctool, "  [-w width] is the data width (8 or 16 decimal).  " "Default: 8 Current: %d\n", i2ctool->width);
	i2ctool_printf(i2ctool, "  [-s|n], send/don't send start between command and data.  " "Default: -n Current: %s\n", i2ctool->start ? "-s" : "-n");
	i2ctool_printf(i2ctool, "  [-i|j], Auto increment|don't increment regaddr on repititions.  " "Default: NO Current: %s\n", i2ctool->autoincr ? "YES" : "NO");
	i2ctool_printf(i2ctool, "  [-f freq] I2C frequency.  " "Default: %d Current: %d\n", CONFIG_I2CTOOL_DEFFREQ, i2ctool->freq);
	i2ctool_printf(i2ctool, "\nNOTES:\n");
#ifndef CONFIG_DISABLE_ENVIRON
	i2ctool_printf(i2ctool, "o An environment variable like $PATH may be used for any argument.\n");
#endif
	i2ctool_printf(i2ctool, "o Arguments are \"sticky\".  For example, once the I2C address is\n");
	i2ctool_printf(i2ctool, "  specified, that address will be re-used until it is changed.\n");
	i2ctool_printf(i2ctool, "\nWARNING:\n");
	i2ctool_printf(i2ctool, "o The I2C dev command may have bad side effects on your I2C devices.\n");
	i2ctool_printf(i2ctool, "  Use only at your own risk.\n");
	return OK;
}

/****************************************************************************
 * Name: i2ccmd_unrecognized
 ****************************************************************************/

static int i2ccmd_unrecognized(FAR struct i2ctool_s *i2ctool, int argc, char **argv)
{
	i2ctool_printf(i2ctool, g_i2ccmdnotfound, argv[0]);
	return ERROR;
}

/****************************************************************************
 * Name: i2c_execute
 ****************************************************************************/

static int i2c_execute(FAR struct i2ctool_s *i2ctool, int argc, char *argv[])
{
	const struct cmdmap_s *cmdmap;
	const char *cmd;
	cmd_t handler;
	int ret;

	/* The form of argv is:
	 *
	 * argv[0]:      The command name.  This is argv[0] when the arguments
	 *               are, finally, received by the command vtblr
	 * argv[1]:      The beginning of argument (up to MAX_ARGUMENTS)
	 * argv[argc]:   NULL terminating pointer
	 */

	/* See if the command is one that we understand */

	cmd = argv[0];
	handler = i2ccmd_unrecognized;

	for (cmdmap = g_i2ccmds; cmdmap->cmd; cmdmap++) {
		if (strcmp(cmdmap->cmd, cmd) == 0) {
			handler = cmdmap->handler;
			break;
		}
	}

	ret = handler(i2ctool, argc, argv);
	return ret;
}

/****************************************************************************
 * Name: i2c_argument
 ****************************************************************************/

FAR char *i2c_argument(FAR struct i2ctool_s *i2ctool, int argc, char *argv[], int *pindex)
{
	FAR char *arg;
	int index = *pindex;

	/* If we are at the end of the arguments with nothing, then return NULL */

	if (index >= argc) {
		return NULL;
	}

	/* Get the return parameter */

	arg = argv[index];
	*pindex = index + 1;

#ifndef CONFIG_DISABLE_ENVIRON
	/* Check for references to environment variables */

	if (arg[0] == '$') {
		/* Return the value of the environment variable with this name */

		FAR char *value = getenv(arg + 1);
		if (value) {
			return value;
		} else {
			return (FAR char *)"";
		}
	}
#endif

	/* Return the next argument. */

	return arg;
}

/****************************************************************************
 * Name: i2c_parse
 ****************************************************************************/

int i2c_parse(FAR struct i2ctool_s *i2ctool, int argc, char *argv[])
{
	FAR char *newargs[MAX_ARGUMENTS + 2];
	FAR char *cmd;
	int nargs;
	int index;

	/* Parse out the command, skipping the first argument (the program name) */

	index = 1;
	cmd = i2c_argument(i2ctool, argc, argv, &index);

	/* Check if any command was provided */

	if (!cmd) {
		/* An empty line is not an error and an unprocessed command cannot
		 * generate an error, but neither should they change the last
		 * command status.
		 */

		return i2ccmd_help(i2ctool, 0, NULL);
	}

	/* Parse all of the arguments following the command name. */

	newargs[0] = cmd;
	for (nargs = 1; nargs <= MAX_ARGUMENTS; nargs++) {
		newargs[nargs] = i2c_argument(i2ctool, argc, argv, &index);
		if (!newargs[nargs]) {
			break;
		}
	}
	newargs[nargs] = NULL;

	/* Then execute the command */

	return i2c_execute(i2ctool, nargs, newargs);
}

/****************************************************************************
 * Name: i2c_setup
 ****************************************************************************/

static inline int i2c_setup(FAR struct i2ctool_s *i2ctool)
{
	/* Initialize the output stream */

#ifdef CONFIG_I2CTOOL_OUTDEV
	i2ctool->ss_outfd = open(CONFIG_I2CTOOL_OUTDEV, O_WRONLY);
	if (i2ctool->ss_outfd < 0) {
		fprintf(stderr, g_i2ccmdfailed, "open", errno);
		return ERROR;
	}

	/* Create a standard C stream on the console device */

	i2ctool->ss_outstream = fdopen(i2ctool->ss_outfd, "w");
	if (!i2ctool->ss_outstream) {
		fprintf(stderr, g_i2ccmdfailed, "fdopen", errno);
		return ERROR;
	}
#endif

	return OK;
}

/****************************************************************************
 * Name: i2c_teardown
 *
 * Description:
 *   Close the output stream if it is not the standard output stream.
 *
 ****************************************************************************/

static void i2c_teardown(FAR struct i2ctool_s *i2ctool)
{
	fflush(OUTSTREAM(&g_i2ctool));

#ifdef CONFIG_I2CTOOL_OUTDEV
	fclose(i2ctool->ss_outstream);
#endif
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: i2c_main
 ****************************************************************************/

#ifdef CONFIG_BUILD_KERNEL
int main(int argc, FAR char *argv[])
#else
int i2c_main(int argc, char *argv[])
#endif
{
	/* Verify settings */

	if (g_i2ctool.bus < CONFIG_I2CTOOL_MINBUS || g_i2ctool.bus > CONFIG_I2CTOOL_MAXBUS) {
		g_i2ctool.bus = CONFIG_I2CTOOL_MINBUS;
	}

	if (g_i2ctool.addr < CONFIG_I2CTOOL_MINADDR || g_i2ctool.addr > CONFIG_I2CTOOL_MAXADDR) {
		g_i2ctool.addr = CONFIG_I2CTOOL_MINADDR;
	}

	if (g_i2ctool.regaddr < CONFIG_I2CTOOL_MAXREGADDR) {
		g_i2ctool.regaddr = 0;
	}

	if (g_i2ctool.width != 8 && g_i2ctool.width != 16) {
		g_i2ctool.width = 8;
	}

	if (g_i2ctool.freq == 0) {
		g_i2ctool.freq = CONFIG_I2CTOOL_DEFFREQ;
	}

	/* Parse process the command line */

	i2c_setup(&g_i2ctool);
	(void)i2c_parse(&g_i2ctool, argc, argv);

	i2ctool_flush(&g_i2ctool);
	i2c_teardown(&g_i2ctool);
	return OK;
}

/****************************************************************************
 * Name: i2ctool_printf
 *
 * Description:
 *   Print a string to the currently selected stream.
 *
 ****************************************************************************/

int i2ctool_printf(FAR struct i2ctool_s *i2ctool, const char *fmt, ...)
{
	va_list ap;
	int ret;

	va_start(ap, fmt);
	ret = vfprintf(OUTSTREAM(i2ctool), fmt, ap);
	va_end(ap);

	return ret;
}

/****************************************************************************
 * Name: i2ctool_write
 *
 * Description:
 *   write a buffer to the currently selected stream.
 *
 ****************************************************************************/

ssize_t i2ctool_write(FAR struct i2ctool_s *i2ctool, FAR const void *buffer, size_t nbytes)
{
	ssize_t ret;

	/* Write the data to the output stream */

	ret = fwrite(buffer, 1, nbytes, OUTSTREAM(i2ctool));
	if (ret < 0) {
		dbg("[%d] Failed to send buffer: %d\n", OUTFD(i2ctool), errno);
	}
	return ret;
}

/****************************************************************************
 * Name: i2ctool_flush
 *
 * Description:
 *   Flush buffered I/O to the currently selected stream.
 *
 ****************************************************************************/

void i2ctool_flush(FAR struct i2ctool_s *i2ctool)
{
	fflush(OUTSTREAM(i2ctool));
}
